- ID:
- ivo://CDS.VizieR/J/A+A/647/A157
- Title:
- Stellar parameters of the EXPRESS sample
- Short Name:
- J/A+A/647/A157
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- As part of the search for planets around evolved stars, we can understand planet populations around significantly higher-mass stars than the Sun on the main sequence. This population is difficult to study any other way, particularly with radial-velocities since these stars are too hot and rotate too fast to measure precise velocities. Here we estimate stellar parameters for all of the giant stars from the EXPRESS project, which aims to detect planets orbiting evolved stars, and study their occurrence rate as a function of stellar mass. We analyse high resolution echelle spectra of these stars, and compute the atmospheric parameters by measuring the equivalent widths for a set of iron lines, using an updated method implemented during this work. Physical parameters are computed by interpolating through a grid of stellar evolutionary models, following a procedure that carefully takes into account the post-MS evolutionary phases. Probabilities of the star being in the red giant branch (RBG) or the horizontal branch (HB) are estimated from the derived distributions. Results: We find that, out of 166 evolved stars, 101 of them are most likely in the RGB phase, while 65 of them are in the HB phase. The mean derived mass is 1.41 and 1.87M_{sun}_ for RGB and HB stars, respectively. To validate our method, we compared our results with interferometry and asteroseismology studies. We find a difference in the radius with interferometry of 1.7%. With asteroseismology, we find 2.4% difference in logg, 1.5% in radius, 6.2% in mass, and 11.9% in age. Compared with previous spectroscopic studies, and find a 0.5% difference in Teff, 1% in logg, and 2% in [Fe/H]. We also find a mean mass difference with respect to the EXPRESS original catalogue of 16%. We show that the method presented here can greatly improve the estimates of the stellar parameters for giant stars compared to what was presented previously.
Number of results to display per page
Search Results
- ID:
- ivo://CDS.VizieR/J/ApJS/100/105
- Title:
- Stellar velocity dispersions. II.
- Short Name:
- J/ApJS/100/105
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- A catalog of central velocity dispersion measurements is presented, current through 1993 September. The catalog includes 2474 measurements of 1563 (*) galaxies. A standard set of 86 galaxies is defined, consisting of galaxies with at least three reliable concordant measurements. It is suggested that future studies observe some of these standard galaxies so that different studies can be normalised to a consistent system. All measurements are reduced to a normalized system using these standards. (*) Actually 1562 galaxies.
- ID:
- ivo://CDS.VizieR/J/ApJ/850/66
- Title:
- Stripe 82X survey multiwavelength catalog
- Short Name:
- J/ApJ/850/66
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- Multiwavelength surveys covering large sky volumes are necessary to obtain an accurate census of rare objects such as high-luminosity and/or high-redshift active galactic nuclei (AGNs). Stripe 82X is a 31.3 X-ray survey with Chandra and XMM-Newton observations overlapping the legacy Sloan Digital Sky Survey Stripe 82 field, which has a rich investment of multiwavelength coverage from the ultraviolet to the radio. The wide-area nature of this survey presents new challenges for photometric redshifts for AGNs compared to previous work on narrow-deep fields because it probes different populations of objects that need to be identified and represented in the library of templates. Here we present an updated X-ray plus multiwavelength matched catalog, including Spitzer counterparts, and estimated photometric redshifts for 5961 (96% of a total of 6181) X-ray sources that have a normalized median absolute deviation, {sigma}_nmad_=0.06, and an outlier fraction, {eta}=13.7%. The populations found in this survey and the template libraries used for photometric redshifts provide important guiding principles for upcoming large-area surveys such as eROSITA and 3XMM (in X-ray) and the Large Synoptic Survey Telescope (optical).
- ID:
- ivo://CDS.VizieR/J/A+A/626/A61
- Title:
- Structural parameters of galaxies
- Short Name:
- J/A+A/626/A61
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- High-resolution multi-wavelength photometry is crucial to explore the spatial distribution of star formation in galaxies and understand how these evolve. To this aim, in this paper we exploit the deep, multi-wavelength Hubble Space Telescope (HST) data available in the central parts of the GOODS fields and study the distribution of star formation activity and mass in galaxies located at different positions with respect to the Main Sequence (MS) of star-forming galaxies. Our sample consists of galaxies with stellar mass >=10^9.5^M_{sun}_ in the redshift range 0.2<=z<=1.2. Exploiting 10-band photometry from the UV to the near-infrared at HST resolution, we derive spatially resolved maps of galaxies properties, such as stellar mass and star formation rate and specific star formation rate, with a resolution of 0.16arcsec. We find that the star formation activity is centrally enhanced in galaxies above the MS and centrally suppressed below the MS, with quiescent galaxies (1dex below the MS) characterised by the highest suppression. The sSFR in the outer region does not show systematic trends of enhancement or suppression above or below the MS. The distribution of mass in MS galaxies indicates that bulges are growing when galaxies are still on the MS relation. Galaxies below the MS are more bulge-dominated with respect to MS counterparts at fixed stellar mass, while galaxies in the upper envelope are more extended and have Sersic indexes that are always smaller than or comparable to their MS counterparts. The suppression of star formation activity in the central region of galaxies below the MS hints at inside-out quenching, as star formation is still ongoing in the outer regions.
- ID:
- ivo://CDS.VizieR/J/ApJ/787/24
- Title:
- Structural parameters of true edge-on galaxies
- Short Name:
- J/ApJ/787/24
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- We present a catalog of true edge-on disk galaxies automatically selected from the Seventh Data Release of the Sloan Digital Sky Survey (SDSS, Cat. II/294). A visual inspection of the g, r, and i images of about 15000 galaxies allowed us to split the initial sample of edge-on galaxy candidates into 4768 (31.8% of the initial sample) genuine edge-on galaxies, 8350 (55.7%) non-edge-on galaxies, and 1865 (12.5%) edge-on galaxies not suitable for simple automatic analysis because these objects either show signs of interaction and warps, or nearby bright stars project on it. We added more candidate galaxies from RFGC, EFIGI, RC3, and Galaxy Zoo catalogs found in the SDSS footprints. Our final sample consists of 5747 genuine edge-on galaxies. We estimate the structural parameters of the stellar disks (the stellar disk thickness, radial scale length, and central surface brightness) in the galaxies by analyzing photometric profiles in each of the g, r, and i images. We also perform simplified three-dimensional modeling of the light distribution in the stellar disks of edge-on galaxies from our sample. Our large sample is intended to be used for studying scaling relations in the stellar disks and bulges and for estimating parameters of the thick disks in different types of galaxies via the image stacking. In this paper, we present the sample selection procedure and general description of the sample.
- ID:
- ivo://CDS.VizieR/J/MNRAS/414/3699
- Title:
- Study of hot stellar systems and galaxies
- Short Name:
- J/MNRAS/414/3699
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- We present a complete picture of dynamically hot stellar systems, ranging from faint galaxies and star clusters of only a few hundred solar masses up to giant elliptical galaxies, in particular including large samples of compact elliptical galaxies (cEs), ultra-compact dwarf galaxies (UCDs), dwarf elliptical galaxies (dEs) of nearby galaxy clusters, and Local Group ultra-faint dwarf spheroidal galaxies (dSphs). For all those stellar systems we show the effective radius-luminosity, effective radius-stellar mass, and effective mass surface density-stellar mass plane.
- ID:
- ivo://CDS.VizieR/J/MNRAS/454/1086
- Title:
- Study of the COSC Korean astronomical catalogue
- Short Name:
- J/MNRAS/454/1086
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- The study of old star catalogues provides important astrometric data. Most of the researches based on the old star catalogues were manuscript published in Europe and from Arabic/Islam. However, the old star catalogues published in East Asia did not get attention. Therefore, among the East Asian star catalogues we focus on a particular catalogue recorded in a Korean almanac. Its catalogue contains 277 stars that are positioned in a region within 10{deg} of the ecliptic plane. The stars in the catalogue were identified using the modern Hipparcos catalogue (Cat. I/239). We identified 274 among 277 stars, which is a rate of 98.9 percent. The catalogue records the epoch of the stars' positions as AD 1396.0. However, by using all of the identified stars we found that the initial epoch of the catalogue is AD 1363.1+/-3.2. In conclusion, the star catalogue was compiled and edited from various older star catalogues. We assume a correlation with the Almagest by Ptolemaios. This study presents newly analysed results from the historically important astronomical data discovered in East Asia. Therefore, this star catalogue will become important data for comparison with the star catalogues published in Europe and from Arabic/Islam.
- ID:
- ivo://CDS.VizieR/J/ApJS/176/1
- Title:
- Subaru/XMM-Newton deep survey (SXDS). II.
- Short Name:
- J/ApJS/176/1
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- We present multi-wave band optical imaging data obtained from observations of the Subaru/XMM-Newton Deep Survey (SXDS). The survey field, centered at RA=02:18:00, DE=-05:00:00, has been the focus of a wide range of multiwavelength observing programs spanning from X-ray to radio wavelengths. A large part of the optical imaging observations are carried out with Suprime-Cam on Subaru Telescope at Mauna Kea in the course of Subaru Telescope "Observatory Projects".
- ID:
- ivo://CDS.VizieR/J/MNRAS/411/505
- Title:
- Sub-mm observations in Extended Chandra DFS
- Short Name:
- J/MNRAS/411/505
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- We present a joint analysis of the overlapping Balloon-borne Large Aperture Submillimetre Telescope (BLAST) 250, 350, 500um, and LABOCA 870um observations [from the LABOCA ECDFS Submm Survey (LESS) survey] of the Extended Chandra Deep Field-South. Out to z~3, the BLAST filters sample near the peak wavelength of thermal far-infrared (FIR) emission from galaxies (rest-frame wavelengths ~60-200um), primarily produced by dust heated through absorption in star-forming clouds. However, identifying counterparts to individual BLAST peaks is very challenging, given the large beams [full-width at half-maximum (FWHM) 36-60 arcsec]. In contrast, the ground-based 870um observations have a significantly smaller 19 arcsec FWHM beam, and are sensitive to higher redshifts (z~1-5, and potentially beyond) due to the more favourable negative K-correction. We use the LESS data, as well as deep Spitzer and VLA imaging, to identify 118 individual sources that produce significant emission in the BLAST bands.
- ID:
- ivo://CDS.VizieR/J/AJ/122/2222
- Title:
- Superclusters of Abell and X-ray clusters
- Short Name:
- J/AJ/122/2222
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- We present a new catalog of superclusters of Abell clusters out to a redshift of z_lim_=0.13, a catalog of X-ray clusters located in superclusters determined by Abell clusters, and a list of additional superclusters of X-ray clusters. We investigate the distribution of X-ray selected clusters of galaxies with respect to superclusters determined by Abell clusters of galaxies and show that the distribution of X-ray clusters follows the supercluster-void network determined by Abell clusters. We find that X-ray clusters are more strongly clustered than other clusters: the fraction of X-ray clusters is higher in rich superclusters, and the fraction of isolated X-ray clusters is lower than the fraction of isolated Abell clusters. Poor, non-Abell X-ray clusters follow the supercluster-void network as well: these clusters are embedded in superclusters determined by Abell clusters and populate filaments between them. This catalogue supersedes J/A+AS/123/119
